1. Field of the Invention
The present invention relates to a sample manipulating apparatus for observing a sample (manipulation object) placed on a surface of a substrate, thereafter, manipulating the sample based on an observation data.
2. Description of the Related Art
There is known a scanning probe microscope (SPM) of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or the like for measuring various kinds of samples of an electronic material, an organic material or the like at a small region, observing surface shapes of the samples and measuring physical property information. The scanning probe microscope is accurate also as a three-dimensional positioning mechanism, and therefore, various proposals have been made for applying the scanning probe microscope as a working apparatus of working a small region.
There has already been developed a working apparatus referred to as an AFM tweezers for positioning a sample between two pieces of probes and grasping or releasing the sample as an application to manipulation of the sample using a scanning probe microscope.
There is known one of AFM tweezers of this kind utilizing a cantilever used in a scanning probe microscope or the like. For example, there is known an AFM tweezers attaching two pieces of carbon nanotubes onto a stylus provided at a front end of a cantilever comprising silicon. Further, there is also known other AFM tweezers attaching two pieces of carbon nanotubes to a glass tube as a cantilever, as well as an AFM tweezers fabricating two pieces of cantilevers by using an MEMS (Micro Electro Mechanical System) process from a silicon substrate or the like.
Among them, in the case of the AFM tweezers having two pieces of carbon nanotubes, two pieces of the carbon nanotubes are opened and closed normally by applying static electricity between two pieces of the carbon nanotubes. On the other hand, in the case of the AFM tweezers fabricating two pieces of the cantilevers by the MEMS process, two piece of the cantilevers are opened and closed by utilizing an electrostatic actuator in a comb teeth-like shape, or two pieces of the cantilevers are opened and closed by enlarging linear expansion of silicon by generating heat by making a current flow to roots of the cantilevers (Transaction of the Institute of Electrical Engineers of Japan, E 2005; Vol 125-No. 11, “Development of AFM tweezers for manipulating nano substance” TAKEGAWA et al) Nonpatent Reference 1).
However, according to the above-described AFM tweezers, the following problem still remains.
Generally, when a sample is grabbed by an AFM tweezers, there is frequently a case in which a hardness, a size or the like of the sample to be grasped has not been found beforehand. However, according to any of the above-described AFM tweezers, the sample is grasped or released simply by opening or closing the carbon nanotubes or the cantilevers, and therefore, it is difficult to carry out manipulation in correspondence with the hardness or the size of the sample.
Therefore, in a case of a soft sample, the sample is frequently deformed or crashed to destruction by a grasping force of the tweezers. Further, in a case of a hard sample, there is a case in which the sample is flipped to move to another location. Particularly, in a case of a strong grasping force, the movement is significant. Further, when a grasping position is not pertinent, there is a case that the sample is moved to another location. When the sample is moved in this way, it is necessary to position tweezers and a sample again, and therefore, an efficient operation cannot be carried out.
Furthermore, even when the sample can presumably be grasped and moved to a predetermined location, in detaching the AFM tweezers from the sample, there is a possibility of adhering the sample thereto; and therefore, it is difficult to detect whether the carbon nanotube or the cantilever and the sample are firmly detached and the detachment has correctly been finished.